What is inversion?
Inversion is a thinking tool where you flip the question. Instead of "how do I make this succeed?", you ask "what would guarantee this fails?" — and then systematically avoid those things. Charlie Munger, who popularized it, put it as: "All I want to know is where I'm going to die, so I'll never go there."
Why it matters
Hard problems are often hard because the path to success is foggy while the paths to failure are obvious. Avoiding stupidity is easier than seeking brilliance, and it compounds: a plan that has quietly removed its ten most likely failure modes beats a clever plan that ignored them.
An example
You want a product launch to go well. Forward thinking produces a vague checklist. Inverted, you ask: "how would I make this launch definitely fail?" — ship with no one testing checkout, announce when your audience is asleep, ignore the first ten complaints. Each answer becomes a concrete safeguard.
How to practice it
Take one decision you're facing today and write down five ways to guarantee it goes badly, then check which of those you're currently doing. Too Hard Pile trains inversion across four difficulty levels — from everyday habits to careers, money, and failure modes disguised as virtues — with short drills that make you commit to an answer before revealing anything.
Reading about mental models doesn't build the reflex — reps do. Too Hard Pile schedules each drill back with spaced repetition so the model is there when a real decision needs it.